


Newton's third law

by Slenbee



Series: Kinktober 2017 [3]
Category: Iron Man (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies), Thor (Movies)
Genre: Biting, Fluff, Hand Jobs, KINKTOBER2017, Kinktober, Loki Does What He Wants, M/M, Masturbation, Porn With Plot, Public Sex, Smut, Tony Stark Has A Heart, Wordcount: 1.000-5.000
Language: English
Status: Completed
Published: 2017-10-03
Updated: 2017-10-03
Packaged: 2019-01-08 16:09:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,296
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12257715
Author URL: https://archiveofourown.org/users/Slenbee/pseuds/Slenbee
Summary: Kinktober2017 - Day 3Tony likes to make promises. So when the mortal promises Loki that his first time at the beach would be perfect, the God certainly expects no less. Of course, nothing goes as planned when Tony's actions have a negative reaction. Ignoring his boyfriend? Certainly not one of his better ideas. Mistakes were made, but thankfully, Loki knows just how to make up for it.





	Newton's third law

**Author's Note:**

> SO I'm going to apologize in advance for the plotbunnies going wild in this fic. I know it might seem like it's all Plot and no Porn, but trust me, it's there. Hopefully you guys can forgive me. :'))

It was odd, to say the least.

No matter how many times Loki tried to make sense of the strange fascination mortals had with lying on towels in rows like carcasses left out to dry, he still couldn’t find the appeal in it. The sun was hot, that was a given. The sand, even hotter. And Loki? He didn’t exactly do well with _heat._

A simple question was all it took to brighten up those big, brown eyes with wonderment. _No way._ Tony told himself, unable to hide his gasp of disbelief and the wide smile that followed. “You’ve never been to a _beach?_!”

Asgard didn’t exactly have beaches. Nor was the Jotunn entirely thrilled with the concept of being in such a vulnerable state around so many people. Being without his armor or weapons around one person was enough. Sometimes two, if Miss Potts came to visit. Standing with his arms folded defensively across his chest Loki watched the short Avenger pace back and forth, ranting and raving about how he was ‘missing out‘ and how there were ‘so many cool things‘ they could do on the boardwalk together. Curling his lip he scoffed and looked away, staring at the wall at nothing in particular. Maybe if he stayed silent long enough Stark would stop asking.

He hated this idea. He _hated_ it.

Tony stopped his pacing, the words on his tongue dying the moment he looked up. _Man.._ Loki actually seemed upset at the idea. Or was that just his normal unamused face? He couldn’t recall. The guy went through moods like Bruce did his shirts. Shifting his weight from one foot to the other the Engineer cleared his throat and managed a weak smile. Carefully he stepped closer, worn hands coming to rest on the Trickster’s crossed arms. Hesitantly rose to the tips of his toes, his voice hushed, coaxing. “ _Hey,_ trust me with this, okay? It’ll be fun, I promise. “ Leaning in he stole a kiss to his God’s chin, his smile widening when he felt the other relax. “We’ll only be at the beach for an hour or two. Okay? Then we can go get cleaned up and head to the boardwalk. We’ll have a nice dinner and- oh!” Wiggling his rump playfully he let out a chuckle. “ We can even stay and watch the fireworks after some ice cream. I’ll buy you any flavor you want. All of them if you’re feeling cheeky. How does that sound? ...Snowflake? “

Pale features softened, the tension in his shoulders dissolving. _Stars above,_ he couldn’t stay mad at Tony like this. Not with those big, brown, puppy dog eyes blinking up at him. Deep down Loki knew he meant no harm in asking. He just got a little too excited sometimes, and his persistence could be a little overbearing. No matter the circumstance, however, Anthony was always so good to him. Always. At the first hint or sign of the God getting nervous or uncomfortable out in public, he always made sure to shoo any offending paparazzi or fans before calling Happy to come pick them up. Any other day to the public eye he was Tony Stark, Genius, Billionaire, Playboy, Philanthropist. But when he was with Loki?

He just wanted to be... Tony.

A mortal man doing everything he could to make his alien boyfriend happy.

Dark lashes fluttered, casting those blue eyes in shadow as the Jotunn shook away his thoughts, his arms unfolding from their defensive position. Rather than let them fall, his hands sought out the warmth of Tony’s own. Lacing them together, he opened his eyes, a smile tugging at the corner of his lips. One day couldn’t hurt, right? Sucking in a deep breath it left his nose in a rush, their eyes meeting. “ Alright. “ A breathy sound escaped when he saw the way his lover’s eyes lit up. “ But **_only_ ** for a few hours. If anything ruins our day I’m expecting payback on the spot. In _full._ “ Dipping his head he stole a kiss from those smiling lips and released Tony’s captured hands.

A bubbly laugh of excitement filled the air as the shorter male rocked back on his heels and clapped his hands together. “ Yeah! You got it Snowflake, don’t worry. I’m gonna’ make sure our evening is perfect. We’re going to have soooo much fun! ” In a hurry he scurried away, disappearing into the bedroom where his voice dropped to a near whisper and his expression became filled with worry. “ _Nothing’s going to go wrong. It better_ **_not_ ** _go wrong. I promise I’m gonna’ make this one of the best days of your life._ ”

Ohh just how wrong he was.

*****

“ _Tony…_ ” There was a warning in Loki’s voice.

Not even an hour and a half into their evening, and he already knew that he had fucked up.

It wasn’t _him_ , per se. Not.. Not exactly, or so he told himself. The steadily growing crowd of families that had gathered around them left him distracted, the occasional approach of a young child with a picture wanting an autograph too cute to refuse in the Avenger’s eyes. They were just kids! He told himself. But as a result? He lost sight of the whole reason they were even there in the first place. _Loki._

All around them there were people watching, whispering, pointing fingers and taking pictures. The last of which left the God’s blood feeling like ice within his veins each time he saw a camera. No matter where he turned, which way he looked, there was always a phone pointed in their direction. Distracting himself with the large book he’d towed along in their bag, he buried his face into it as far as it could go, watching from the corner of his eye as the mortal beside him smiled and shook hands with a young boy and his mother. That’s how it always starts. You feed the children and suddenly the parents are swarming around you like flies.

_Can I get an autograph Mr. Stark? Tony! Can my boyfriend and I take a selfie with you?!_

Movement caught the Iron Avenger’s gaze, his attention drifting over to the man beside him, the smile upon his lips wilting almost instantly. _Shit. Fuck. God damn it..._ “ I… I’m sorry everyone. “ Blinking up at the crowd he waved the paper in his hand. “No more autographs or pictures, please. My.. “ He hesitated and looked to Loki, only when one of those blue eyes made contact with his did he furrow his brow apologetically. “ My _boyfriend_ and I had plans this evening, and I’d like it if we were left alone. “ Watching anxiously he saw the Jotunn relax with a slow blink and a smile that was barely there. There was his Lolo. Blinking away the human cleared his throat and nodded. “ Okay? Okay. Sorry guys. Maybe another time. Off you go. “ Quickly scribbling his signature beside the stick figure rendition of himself he handed it back and smiled at the boy who was promptly pulled away by his mother.

Right. No more distractions. He made a promise god damn it. Clicking the pen he tossed it into the bag between the two. “ I’m, I’m _sorry,_ Loki. I… “ There was no avoiding this now. Sighing he closed his eyes and pinched his nose.  “ I fucked up, big time. And I know I don’t deserve your forgiveness for that. I promised... “ _Ughh what was the point._ Why was it during the most important moments of his life did he do shit like this? The last time he did something like this was when he was with-- A cool palm settled atop heated shoulder, jolting him out of his thoughts at the sudden, sharp contrast of temperatures. Lifting those worried, brown eyes, he noticed that the book that Loki had once shielded himself with now closed within his lap. When had he moved? It didn’t matter.

“ I know, Anthony. But it is a habit not so easily broken. “ Nimble fingers spread wide, giving the mortal’s bicep a reassuring squeeze, his smile just as tender. “ You thrive in places like this. Like a flower does beneath the sun. It is not my place to take that away from you, nor would I ever try to do so. “ Loki may have been selfish in many ways, but he could not keep Tony all to himself, locked away with no interaction. He did that enough to himself when he spent weeks on end down in his workshop with little food or water, let alone a shower!

Lifting a hand he set it atop the God’s own, shoulders sagging with relief with each word that left those pretty, pink lips. “ Yeah… I guess you’re right. “ Sniffling with a blink he peered out at the ocean, watching the waves that lapped at the sand, his mind blocking out the people scattered here. None of them mattered, only Loki did. A thought sparked and his breath hitched, his smile becoming an overly confident smirk. “ A flower huh? Y’know a flower also needs plenty of water, and you’re a tall glass of it. If I do say so myself~ _Ow!_ Hey!! “ His comment earned a snort and a playful smack to his arm, a pouting whine following as he rubbed the stinging spot.

“ Keep giving me compliments like _that_ and you’re going to drown. Now come, help me gather our things. We have the rest of the evening ahead of us and I’m famished. “ Tucking his book back inside of the large bag between them, the Trickster gathered up the empty cans of soda and snacks to be thrown away once they reached the boardwalk while Tony dusted off the pillows and packed away the sunscreen.“ By the **way** , “ Tony had the corner of his blanket in his mouth, a curious sound escaping as he let go and continued to fold it, his gaze lifting. A lazy smile tugged at Loki’s lips, those pearly whites giving a subtle flash. “ Once we get to the showers, I expect you to make up for your little... _incident_. “

Baffled by the demand Tony blushed and swallowed the sudden knot in his throat. _Ohhh f-fuck._ He knew that tone of voice. If he wasn’t in trouble then, he most definitely was now.

Except this time, he was actually looking _forward_ to it.

*****

Like Tony, Loki was clever in his own ways. On one hand, there wasn’t a situation he couldn’t get out of, and on the other? There were way too many that he couldn’t _wait_ to get into. The beach itself offered little to no privacy at all, the small crowd of people that had gathered now following  the two of them as they left the sandy shores and ventured farther inland. They arrived at a  modestly sized building with five doors on either side. Each one served as a changing room with a built-in shower, a waterproof locker built into the wall to keep clean clothes and other belongings dry. It would be a tight fit, but the two of them could make do.

With one arm looped within Tony’s and the other carrying their bag he pulled his beloved along, ignoring the gasps and squeals of surprise that followed. Yes yes, it was the ‘famous’ Iron Man. On ‘their’ beach, how ‘lucky’ for them. He had more important business to attend to! The door to the last stall was slightly ajar as they approached, and without much else he was freeing himself before they arrived, opening the door for the Avenger to duck into before he did the same. Shutting the door he locked it, a low sound escaping his throat when a kiss met his shoulder blades and warm hands settled upon his hips from behind. “ Locker, “ Was the only word he growled out while turning in the other’s grasp, the bag fumbled and almost dropped as it was taken and stuffed away.

Soft murmurs could be heard coming from outside the door, patrons talking while waiting to use the stalls whilst others hummed ‘ Africa’ by Toto as a remix played quietly through the speakers.

Tony was at a loss at what to do. He’d gotten in trouble, and now he was going to pay for it. But how? Loki hadn’t been specific in what he wanted, and in doing so left the Engineer’s mind to go into overdrive, leaving him to pick through the various scenario’s that cropped up. Closing the locker door- _slamming it,_ really, he turned to face Loki, lips parting to speak but instead, he found the Trickster’s own crashing down on him. Frigid hands sought heated hips, his back greeting the locker door as he was roughly pushed against it. When his God proceeded to press up against him, he thought he’d seen stars-- and then realization suddenly hit him.

They were in _public_ , and Loki was doing this on _purpose._

Cool fingertips snaked their way upward, brushing along Tony’s naked ribs, relishing in the way the mortal’s breath quickened beneath his touch. Breaking their kiss the Jotunn watched and listened to the other man gasp, the attention of one hand snaking forward to chastely brush along a perky nipple. When Tony closed his eyes and parted his lips to moan loudly, a finger was soon silencing him. Mischief danced within those silvery eyes with lips curling into a smile that was almost cruel. “ _Ahhh ahh~_ Careful my love, we both know just how noisy you can be in the bedroom. Let’s keep that between you and I, shall we? “ Lowering that digit a chaste smooch was stolen from those lips, the next words that escaped a low whisper. “ _You wouldn’t want your fans to find out about that, would you?_ “

A shudder rolled down Tony’s spine like a bolt of lightning, the hot spark landing in his loins, sparking his arousal with a jolt. _Fuck._ Sure there were video’s of him on Youtube in some very compromising situations. But here? Of all places? Feeling his cheeks burn the shorter male shifted helplessly, a needy huff fluttering free. “ _Sh-shit. Loki, baby. We shouldn’t- hah..!_ “ Furrowing his brow and snapping his jaw shut he arched his back at the second pluck to his nipple, fingers twitching before his hands snapped up to grab the God’s shoulders. Taking a deep breath he tried to calm himself. _C’mon Stark. You are not getting aroused by this. Think of something else. Puppies, kittens, old ladies, Ste-eeeve--!_ Another firm pinch and he was slapping the back of his hand against his mouth, muffling the sharp yelp that nearly burst free.

Seeing that hand cover the mouth that his darling Avenger just loved to use, Loki couldn’t help but chuckle. As much as he relished in the idea of his cock being a far more suitable method of keeping him quiet, now just simply wasn’t the time. Silver hues drifted southward, grazing over toying fingers before settling upon the hard evidence of arousal that strained against ruby red swim trunks. Lowering his free hand he took hold of him through the fabric, a sharp buck of hips greeting him as he did so. “ _What was it you told me a few weeks ago, my darling Anthony? That I had such... sensitive nipples?_ “ He whispered lowly. Tweaking and pulling on that bud Tony’s body arched and thrust against him, his panted moans muffled behind his hand. “ _Or is it the_ **_location_ ** _that has aroused my darling boy so swiftly, hmm?_  “  Lifting his head Loki’s eyes could just barely see past the holes in the wall that lined every stall, skimming over peoples heads and watching as people came and went. Blinking back down he smiled, leaning in to place a few kisses upon bare shoulder.

 _Jesus Christ_ . Sure Tony thought Loki had a lot of things going for him. His height, the combination of feminine and masculine beauty. It made him feel like the luckiest guy in the world. But Gods be damned, when he spoke like _that?_ Poor Tony felt like a giddy teenager going through puberty all over again. With a flutter of lashes his eyes rolled back when cool fingers brushed upon overly sensitive flesh, caressing through the silky fabric of his shorts from root to tip. That hand cupped him beautifully, each roll of his hips providing just enough friction that if he kept going like that-- _Fuck, baby. You’re gonna make me cream my shorts if you keep doing t-that!!_ Just as the fire began to build, it was suddenly swept away. Quickly dropping his hand from his mouth Tony opened his eyes with a huff and a pout, watching as the Jotunn’s hand disappeared. “ _Looh-ohkiiii.._ Snowflake? What are you..? “ Eagerly following the other’s hands with his eyes he found them settling on the taps and- “ _Sh-Shit! Hahh! Thaah-! that’s c-cold Lo-mmph!_ “

Silencing the escalating crack in his lover’s voice with a rough kiss, the God pressed forward, the spray from above falling along his back and shoulders. Once certain the risk of him drawing attention was gone, he pulled away and watched Tony shudder and shiver, a bit of magic warming the waters until he was sighing instead of shaking. “ _Is that better? And here I thought you_ **_liked_ ** _a little cold~_ “ Playfully he nipped that pouting lower lip, wet fingertips snaking along quivering belly until they found their prize once more. Tugging at the waistband of those shorts Loki pulled them down just enough so that Tony’s cock sprang free. When a few cold droplets fell from his hand and onto sensitive flesh, he couldn’t help but giggle as it twitched as a result. “ _Ahh ha, that’s what I thought. Now let me take care of you before your fans come knocking, hm?_ “

Oh, there was no denying that Tony loved the cold. Not in the bedroom, at least. But there again there was quite a large difference between cool skin and literal ice water. Loki he could handle six ways till Sunday. The later? Not so much. Feeling the water grow warm he relaxed, huffing and puffing with his cheeks tinted the most embarrassing shade of red. It was sunburn. Totally not a blush. Yup. Sucking in a deep breath he reclined back against the locker with a sigh, his hands restless at his sides. So, deciding to put them to better use, he reached out for Loki’s own black and green shorts but paused when the other man grew still. “ _May I..? I mean. It’s the least I can do to make earlier up for you. Even if a-ah.._ “ Dabbing his tongue against his lips he eyed the door behind Loki, a rush of heat fanning through him. “ _Anyone could come knocking a-at any moment._ “ Why did he find the idea of being caught so god damn arousing?!

Blinking he searched those big brown eyes filled with eagerness and need, the question that he was prompted with twisting his lips into a smirk. Lowering a hand, he stilled the ones currently fiddling with the string of his own shorts. “ _Ah Ah, “_ He mocked with a teasing tone. “ _I said that I wished to take care of you, my darling boy. Or would you rather be forced to leave early so the world can see just how_ **_hard_ ** _you’ve become?_ “ Earning himself a keen of pleasure, a shudder, and a needy thrust of hips, the Trickster chuckled and took him in hand. With each stroke upward he caressed the sensitive underside of his glans, thumb curling forward to dab and caress that weeping slit. Letting his head fall, the dark-haired god kissed his shoulder. “ _Mmm, imagine if they saw you like this. Pinned beneath me with my hands upon you, stroking you until you cum_ .” Teeth grazed heated flesh, nipping firmly. “ _Would you like that, Anthony? Would you like them to see?_ “

Those words. Oh _god,_ those words. They painted the most beautiful picture within Tony’s overactive mind. Someone bumped into the wall beside them with a _thump_ and he couldn’t help but gasp, jaw clenching as his entire body jerked. “ _No, noo-oohh_ .”  He had to be quiet, he couldn’t let them hear. Turning his head he buried his face in the Jotunn’s hair, panted breath fanning along his ear. “ _I- ah.. I don’t wannnt them to see. Just y-you, only you, Lo- Lookiii…_ “ Nobody else was allowed to see him in such a vulnerable state like this. Loki, and only Loki. Toes curled, hips rocking forward into the coaxing strokes of the cool hand that held him. The lewd sound of each thrust tickling at his ears past the sound of water that fell from above. Feeling his cheeks darken Tony turned his head and shamelessly watched, rutting into his God’s hand, chasing the blissful end that would ignite his nerves and send him over the edge.

Feeling his breath falter within his lungs the Trickster found himself chuckling and smiling against Tony’s skin. His words a purred out whisper.  “ _Fret not my love, I’ll make sure this stays our little secret~_  “ Fingers tightened, eliciting a groan against his ear. Quickening his strokes he gave a slight twist to his wrist and thumbed over the head of his lover’s cock, feathering along the underside with each upward glide. He could feel the quiver in his hips and the erratic twitching that followed, knowing that his beloved mortal was growing close. But being Loki, he wanted to make sure they went out with a _bang._

Teeth sank into his shoulder and like a string drawn too tightly, his entire reality snapped. “ _HAH!_ **_F-FUCK!_ ** “ He shouted, his own hand promptly slapping itself to his mouth, muffling the near scream that followed. Tony’s entire body shook from head to toe, eyes glued on Loki’s hand, watching as sticky ropes of cum painted those pale fingers and his own belly. _Shit, shit..!_ Outside a hard knock came to the door, murmurs of concern drowned out by his own muffled sounds of embarrassment. Hips gave a jolt forward, a few more spurts of pearly seed coaxed free before Loki’s pace finally stilled. If it weren’t for the Trickster holding him up he surely would have fallen to the floor by now!

_Sir? Sir!? Is everything okay in there? Mr. Stark?_

Smiling triumphantly to himself Loki unwound his fingers, leaning out of the spray just far enough so he could lick a few of them clean. With a lazy blink, he smiled over at the Engineer who was blushing so beautifully, eyes wide with fear. His hand never leaving his mouth. Had that just happened? Oh it most certainly did. With his free hand he carefully lifted his shorts back up to cover Tony’s now flaccid member.  “ Yes yes, I apologize for the sudden outburst. My boyfriend seems to have quite the _wicked_ little sunburn. “

_Ah.. Oookay. Th-thank you, sir. Sorry for interrupting!_

The sound of retreating flipflops was followed by several concerned and rather disappointed mutters. Closing his eyes a sigh of relief rushed free, head falling back with a dull thump while his hand fell away from his mouth and to his side. With a low groan, Tony finally spoke. _“ Shit…_ That was close Lolo. _Seriously,_ what if.. “ Hearing the God snort with amusement had him cracking open an eye, a playful shove given to the Jotunn’s shoulder with a huff. “ _Asshole._ That was your plan all along, wasn’t it!! “ Was he mad? Far from it, actually. If his playful smile wasn’t an obvious sign of that. Giving another playful shove he leaned in and stole a kiss to Loki’s chin, savoring the mixture of warm water flowing over him and the comforting chill beneath his lips. Rolling his shoulder a bit he winced and hissed, quickly pulling back. “ Jesus.. “ Touching the spot he furrowed his brow. “ You actually _bit_ me? Loki!! “

Laughter filled the tiny changing room, the hands that came flying at him in the form of a playful assault soon caught by the wrists. “ Your shirt will cover it, and what? Am I not _allowed_ to bite you? Is it some sort of crime for me, your _boyfriend,_ to- _mmph!?_ “ Arms circled his neck, dragging him into a kiss that had him closing his eyes and smiling like a fool.

Pulling away from that kiss Tony wrinkled his nose playfully, fingers running through those inky tresses. “ _Pfft,_ are you kidding? “ Rolling his shoulder he snorted and let go. “ I mean, is it sexy? “ Trying to turn his head and look at it he faked a frown. “ If not I could totally pass it off as a bee sting, or a jellyfish sting, but those usually don’t stop hurting unless you pee on- “ The water went cold, arms suddenly snapping to his chest as he tried to get away from it with a shrill shriek. “ _Aack!_ Oohhkay, okay!! I give up! _Sthaaap!_ “ When the water was finally turned off he was left sputtering and gasping, teeth chattering past parted lips.

Conjuring forth one of the clean towels from their bag, Loki tossed it over Tony’s head, ruffling his hair in the process. “ Good~ Now let's finish up. I’m feeling quite peckish after your little display, and I do believe that _someone_ owes me ice cream. “ A shimmer of magic cascaded along their bodies, whisking away any dirt or grime that may have been left.

Grabbing that towel the Avenger laughed and poked his head free with a waggle of his brow. “ Ice cream before dinner? _Awww yeah_. I’m totally down for that. “ Toweling out his ear he smirked and wiggled an eyebrow. “ Get ready for the best night of your life Snowflake, I’m about to take you on a trip to flavortown~ “


End file.
